The potential role and apoptotic profile of three medicinal plant extracts on Leishmania tropica by MTT assay, macrophage model and flow cytometry analysis

摘要

IntroductionTreatment of leishmaniasis with conventional synthetic drugs is a major global challenge. This study was designed to explore the leishmanicidal activity and apoptotic profile of three leaf extracts onLeishmania tropicastages.MethodsThe plants ofQuercus velutina, Calotropis proceraandNicotiana tabacumwere gathered from Anbarabbad county, in the southeastern part of Kerman province and extracted by maceration method using methanol alcohol. Various concentrations of the extracts (1, 10, 100 and 1000?μg/mL) were used against L.tropicastages to evaluate the inhibitory effect by colorimetric assay, macrophage model and flow cytometry. The MTT assay was conducted to determine the IC50and CC50values in promastigotes and J774-A1 macrophages, respectively. For intra-macrophage amastigotes, the leishmanicidal activity was evaluated by calculating the mean number of amastigotes in each macrophage and also IC50values. The promastigote or amastigote stages with no drug and complete medium without organisms were considered as positive and negative controls, respectively. Meglumine antimoniate (Glucantime) was also used as standard drug. Also, annexin V was used to assess the apoptotic profile. All treatment settings were incubated for a standard time of 72?h in triplicates. Data were analyzed byt-test and ANOVA.ResultsThe findings showed that all plant extracts inhibited the proliferation rate of promastigotes and amastigotes (P? 0.001); especially,Q. velutinarepresented the lowest IC50in both stages. Besides,Q. velutinashowed the least number of amastigotes in each macrophage compared to the other groups (4.5?μg/mL). The percentage of parasitic apoptosis at 1000?μg/mL ofQ. velutina, C. procera, N. tabacumand Glucantime? were 37.4, 18.6, 8.5 and 52.4, respectively. Amastigotes (clinical stage) were significantly more susceptible to extracts and also Glucantime? than promastigotes (P?